Base64 encoding represents binary data in an ASCII string format using 64 characters (A-Z, a-z, 0-9, +, /) plus padding (=). It converts every 3 bytes of input into 4 Base64 characters, expanding data by about 33% but ensuring safe transmission over text-only protocols like HTTP or SMTP. Our tool implements the standard RFC 4648 algorithm, handling edge cases like partial bytes and padding correctly. For files, it reads binary data as an array buffer and encodes it chunk-by-chunk to prevent memory issues with large inputs. Decoding reverses this process, validating the input string to ensure it conforms to Base64 rules before outputting the original data, making it indispensable for web development, API testing, and data serialization tasks.

1. Choose your mode: Encode to convert plain text or files to Base64, or Decode to reverse the process.
2. For text encoding/decoding, simply paste your content into the input field – supports multi-line and special characters.
3. For file operations, upload images, documents, or binaries up to 10MB, and let our tool handle the conversion automatically.
4. Click the respective "Encode" or "Decode" button to process your input in real-time, with results appearing instantly below.
5. Review the output, which includes the Base64 string, original size info, and download options for decoded files.
6. Copy the result with one click or download as a file, ready for integration into your code or data pipeline.

• Web developers embedding small images as Base64 data URIs in CSS or HTML to reduce HTTP requests.
• API testers encoding JSON payloads with special characters for POST requests in tools like Postman.
• Email marketers preparing HTML newsletters with inline CSS and images encoded for compatibility.
• Full-stack engineers serializing binary configs or tokens for storage in databases or config files.
• Security professionals encoding sensitive data snippets for logging or sharing without revealing content.
• Frontend designers converting icons to Base64 for inline SVG usage in responsive components.

• Dual-mode operation: Encode text/files to Base64 or decode strings back to original format with 100% accuracy.
• File upload support for images, PDFs, and binaries – converts large files without size limitations in modern browsers.
• Real-time preview with character count and size comparison to monitor encoding efficiency.
• URL-safe Base64 variant option for web-safe transmission in query parameters and headers.
• Advanced error detection that highlights invalid Base64 input and provides helpful troubleshooting tips.
• Lightweight, no-install required – works entirely in-browser with zero data upload to servers.
• Export options including copy-to-clipboard, file download, and code snippet generation for easy integration.

Base64 encoding embodies MIME standards for binary-text interoperability, mapping 8-bit bytes to 6-bit indices in a 64-symbol alphabet to achieve 4:3 expansion ratio. The algorithm processes input in triplets, using bit shifting and modulo operations for character lookup, with padding (=) for incomplete groups per RFC 4648. Decoding validates alphabet membership and padding, then reconstructs bytes via reverse mapping. This radix-64 scheme, evolved from uuencode, ensures robustness against channel noise in protocols like SMTP, while variants (URL-safe) adapt +/ to -_ for URI compatibility, underpinning web data URIs and embedded resources in modern development ecosystems.

All calculations and data processing for this tool are performed locally in your browser. We do not send any of your data to our servers, ensuring your information remains private and secure.